SIM Simmonston Land System
Area: 50.8 km2
Landscape: Ranges and pediments system at the northern end of the alluvial Willochra plain. The ranges are linear rocky, quartzitic and the pediments which abut them vary from coalesced fans with red clayey soils, to calcareous rises, often on calcareous basement rock. Ironstone gravel occurs in some red soils. Deep weathering profiles exist in some parts of this land system as indicated by the presence of ferruginous layers and mottled, kaolinised zones which have been exposed by erosion in places. Some pediments which are severely scalded and gullied. ABC Range Quartzite occurs in this land system and typically occurs under gentle to moderately undulating pediments and low rises with erodible, red, texture- contrast soils.
Annual rainfall: 250 - 275 mm average
Geology: ABC Range Quartzite mostly with Pound Quartzite forming ridges. Inclusions of other lithologies, such as Cambrian Hawker Group limestones and calc-silicate rocks also occur.
Typical soils: Calcic, red, pedaric Sodosols/Chromosols on pediment slopes and gently undulating summit surfaces; red clayey, pedaric Dermosols and Vertosols often occur in association.
Ironstone gravel amounts range from slight to >50% in surface horizons. Gypsum is often present as a few soft segregations in the subsoil, and may form gypcrete horizons in B-C horizons or weathered rock zone. Very shallow loamy to clay-loamy calcic red Rudosols occur on elongate quartzite ridges typical of this land system. All soils may have extensive gravel as a surface lag and/or throughout the profile.
Main soils: D4 (16%) Loam over pedaric red clay (Pedaric Red Sodosol-Dermosol)
A5 11%) Rubbly calcareous loam on clay (Supracalcic-Lithocalcic Calcarosol on clay) A3 (10%) Deep moderately calcareous loam (Calcic Calcarosol)
D2 (10%) Loam over red clay (Calcic-Hypercalcic Red Chromosol- Sodosol)
Minor soils: A4 (8%) Deep (rubbly) calcareous loam (Hypercalcic-Lithocalcic Calcarosol) L1 (8%) Shallow soil on rock (Rocky Rudosol-Tenosol)
D1 (7%) Loam over clay on rock (Shallow Calcic-Hypercalcic Red Chromosol) A6 (6%) Gradational calcareous clay loam (Pedal Hypercalcic-Lithocalcic Calcarosol on
clayey subsoil) A2 (5%) Calcareous loam on rock (Paralithic Calcarosol)
Summary: Linear rocky range with pediments and fan deposits. Pediments have red clayey texture contrast soils, calcareous soils occur on calcareous colluvia and calc-siltstones and
limestones. Tertiary deep weathering profiles and associated ironstone soils occur in places.
Scalding and gullying is severe in parts of the land system.
Soil Landscape Unit summary: Simmonston Land System (SIM) SLU % of area Component Main
soils Prop# Notes AMO 2.3 Rolling low
hills
L1C2 D Linear ridge trending northwest to southeast of rolling low hills formed on ABC Range Quartzite. Slopes are 10-30%, relief is 30- 90m. Shallow lithosols dominate the ridges and upper slopes, deeper gradational soils occur on mid to lower slopes.
Main soils: Shallow stony soils on rock - L1 and red gradational soils, Red clayey pedaric Dermosols - C2.
AQC 1.1 Rolling low hills
L1 D Hills with shallow rocky soils formed on quartzite, such as ABC Range Quartzite.
AQC Rolling low hills.
Relief is greater than 30m, slopes are 10-30%.
Main soils: Shallow stony soils on rock - L1. Minor Gradational loam on rock - C2, soils also occur.
Mostly non-arable.
AQD Steep low hills as above, with extensive rock outcrop.
Relief is less than 90m, slopes are 30-60%.
Main soils: Shallow stony soils on rock - L1 and Bare rock - RR.
Non-arable.
AQD 4.6 Steep how hills
L1 D
DNW 1.6 Undulating rises
D1 D Rises with red texture soils formed over basement rock. The soils have clay loam and clay surface textures.
DNW Undulating rises with 5-50% of the land affected by scalding.
Relief is less than 30m, slopes are less than 10%.
Main soils: Loam over red clay - D2 and Loam over clay on rock- D1.
EUm 1.7 Undulating Rises
L1C2 A2
D Undulating rises with a complex of red clay-loamy soils and shallow calcareous soils and red gradational-textured soils.
Gullying affects up to 10% of land and up to 50% is scalded.
Relief is less than 30m, slopes are 3-10%.
Main soils: Shallow stony soils on rock - L1, Gradational loam on rock -C2 and Calcareous loam on rock – A2.
EVm 3.8 Undulating rises
A2 V Undulating rises with rocky outcrops. Shallow calcareous loamy soils formed on Cambrian hawker Group limestones and calc- siltstones. Relief is less than 30m, slopes are 3-10%.
Main soils: Calcareous loam on rock – A2 and Bare rock - RR.
Rocky outcrops
RR C
FHV 1.3 Gently undulating plains
J1D4 D FHV Gently undulating plains and plateau remnants on deeply weathered kaolinized rocks. Soils contain ironstone gravelly layers and surface lag.
Nearly 50% of the land is scalded, moderate salinity subsoil occurs.
Slopes are 1-3%, relief is less than 9m.
Main soils: Ironstone soil with calcareous lower subsoil - J1 and Loam over pedaric red clay - D4.
FHm Undulating plains, nearly 20% of land is affected by gullying, and up to 50% is scalded..
Slopes are 3-10%, relief is less than 9m.
Main soils: Ironstone soil with calcareous lower subsoil - J1 and Loam over pedaric red clay - D4.
FHv Gently undulating plains, nearly 20% of land is affected by gullying, and more than 50% is scalded.
Slopes are 1-3%, relief is less than 9m.
Main soils: Ironstone soil with calcareous lower subsoil - J1 and Loam over pedaric red clay - D4.
FHm 4.2 Undulating plains
J1D4 D FHv 3.9 Gently
undulating plains
J1D4 D
JIV 4.3 Gently sloping plain
D4D1 A5
D JIV Gently undulating plain with some shallow stony rises, scalding affects 10-50%. Slopes are 1-3%, relief is less than 9m.
Main soils: Loam over pedaric red clay - D4, Loam over clay on rock- D1, Rubbly calcareous loam on clay - A5.
JMV 4.6 Gently
sloping plain D2D4
A6 D Plains with stony texture-contrast soils, which often have pedaric clay subsoils.
JMV Gently sloping plain, scalding affects 10-50%.
Slopes are 1-3%, relief is less than 9m.
JMk Level plains, up to 20% is gullied, around 50% is scalded.
Slopes are less than 1%.
JMl Gently sloping plains. Up to 20% is gullied, around 20-50% is scalded. Slopes are 1-3%, relief is less than 9m.
JMv Gently sloping plains. Up to 20% is gullied, over 50% is scalded.
Slopes are 1-3%, relief is less than 9m.
Main soils: Loam over red clay - D2, Loam over pedaric red clay - D4 and Gradational calcareous clay loam - A6. Red clay soils are minor components.
Soils fertile, but suffer erosion of thin surface layers, leaving scalds.
JMk 1.3 Plains D2D4
A6 D JMl 11.2 Gently
sloping plain D2D4 A6
D JMv 1.7 Gently
sloping plain D2D4
A6 D
JNV 0.7 Gently sloping pediments
D4D2 A5
D Pediments with non-stony pedaric, texture contrast soils with calcareous subsoils. Surface textures are clay loamy mostly.
JNV Gently sloping pediments. Scalding affects 10-50% of land.
Slopes are 1-3%, relief is less than 9m.
JNn Rolling pediments. Gullying affects 20% of the land, scalding affects up to 10%. Slopes are 10-30%, relief is < 9m.
Main soils: Loam over red clay - D2, Loam over pedaric red clay - D4 and Rubbly calcareous loam on clay - A5. Red clay soils occur in minor association.
JNn 4.4 Rolling pediments
D4D2 A5
D
JZG 0.7 Gently undulating pediment
D4A5 V Pediment-basement rock complex with red texture contrast soils on pediments and 20-30% rocky rises with shallow texture contrast soils.
JZG Gently undulating pediment-basement rises complex, gullying affects 10-20% of land.
Pediments: Slopes are 1-3%, relief is under 9m.
Main soils: Loam over pedaric red clay - D4, Loam over clay on rock- D1 and Loam over red clay - D2 with minor Rubbly calcareous loam on clay - A5.
Rocky rises: Mainly Bare rock - RR.
JZII Rolling pediment- basement rises.
Pediments: Gullying affects >50% of land.
Slopes are 10-30%, relief is less than 9m.
Rocky outcrops: Mainly Bare rock - RR.
JZk Plains-basement rises complex, with very gentle slopes of less than 1%. Nevertheless, gullying affects more than 20% of the pediments and 10-20% of the rises. Scalding affects more than 50% of the pediments and 5% of the rises.
Plains: Main soils: Loam over pedaric red clay - D4, Loam over clay on rock- D1 and Loam over red clay - D2 with minor Rubbly calcareous loam on clay - A5.
Rocky rises: Main soil: Loam over clay on rock- D1
JZl Pediment-basement rises complex, similar in soils and rocky rise occurrence to JZB above. Pediments have gentle slopes of 1- 3%. Gullying affects more than 20% of the pediments and 10-20%
of the rises. Scalding affects more than 50% of the pediments and less than 5% of the rises.
Pediments: Slopes are 1-3%, relief is under 9m.
Rocky outcrops
RR C
JZII 2.1 Rolling pediment
D4A5 V Rocky
outcrops
RR C
JZk 7.1 Plains D4D1
D2 V Rocky rises D1 C JZl 2.2 Gently
undulating pediments
D4D1 D2
V
Rocky rises D1 C
Main soils: Loam over pedaric red clay - D4, Loam over clay on rock- D1 and Loam over red clay - D2 with minor Rubbly calcareous loam on clay - A5.
Rocky rises: Main soil: Loam over clay on rock- D1.
KTV 1.3 Pediment E2C3 D4
D Gently undulating pediment with non-calcareous and calcareous gradational soils. Slopes are 10-30%.
Main soils: Red cracking clay - E2, Friable gradational clay loam - C3 and Loam over pedaric red clay - D4.
Soils are generally inherently fertile.
KLV 11.3 Gently undulating pediment
A5 D Gently undulating pediment with clay loamy calcareous soils.
Scalding affects 5-10% of the land in the map unit.
Slopes are 1-3%, relief is less than 9m.
Main soils: Rubbly calcareous clay loam on clay - A5.
Minor soils: Calcareous clay loam on rock – A2, Gradational red- brown clay loam over rock-C2 and Shallow calcareous loam on calcrete – B2.
KPl 18.2 Gent sloping pediment
A3A4 D Gently Sloping pediment with sandy surface-textured, gradational, calcareous soils. Scalding affects 10-50% of land and up to 5% is gullied. Slopes are 1-3%, relief is less than 9m.
Main soils: Deep moderately calcareous sandy loam - A3 and Deep (rubbly) calcareous sandy loam -A4.
XAZ 4.5 Flood plain M1M3 D4
D Flood plain with mixed alluvium. Soil surfaces are scalded with up to 50% of land affected.
Main soils: Deep alluvial loam - M1, Deep gravelly soil -M3 and Loam over pedaric red clay - D4.
Prone to flooding.
# PROPORTION codes assigned to Soil Landscape Unit (SLU) components:
D Dominant in extent (>90% of SLU) V Very extensive in extent (60–90% of SLU) E Extensive in extent (30–60% of SLU)
C Common in extent (20–30% of SLU) L Limited in extent (10–20% of SLU) M Minor in extent (<10% of SLU)
Detailed soil profile descriptions:
A2/L1 Shallow calcareous loam (Paralithic, Hypercalcic / Lithocalcic Calcarosol)(A2) OR Shallow stony loam (Calcareous, Paralithic, Leptic Tenosol)(L1)
Shallow stony loam, calcareous throughout or with depth, overlying weathering rock shallower than 50 cm.
A3 Deep moderately calcareous (sandy) loam (Calcic Calcarosol)
Calcareous (sandy) loam topsoil grading into loamy-clay loamy subsoil without a significant CO3 buildup in the subsoil (<20% CO3 in subsoil). Pediment type Calcarosols.
A4 Deep (rubbly) calcareous loam (Hypercalcic-Lithocalcic Calcarosol)
Calcareous sandy-clay loamy topsoil grading into loamy-clay loamy subsoil with a significant CO3
buildup in the subsoil. Often rubbly. Soil usually >120 cm in depth
A5 Rubbly calcareous loamy sand on clay (Supracalcic-Lithocalcic Calcarosol on clay)
Calcareous loamy sand topsoil grading into loamy-clay loamy subsoil on a clayey substrate. Usually rubbly. Clayey substrate occurs at >60 cm and <120 cm.
A6 Gradational calcareous clay loam (Pedal Hypercalcic-Lithocalcic Calcarosol) on clayey subsoil Calcareous loams to clay loams grading into brown-red clay. Often rubbly.
B2 Shallow calcareous loam on calcrete (Petrocalcic Calcarosol-Rudosol)
Shallow, grey to reddish calcareous sandy to clay loamy soil on calcrete. This includes calcareous Petrocalcic Rudosols.
C2 Gradational loam on rock (Calcic / Hypercalcic Red Dermosol)
Loam to clay loam grading to a friable red clay with soft Class I carbonate within 50 cm, grading to weathering rock within 100 cm.
C3 Gradational clay loam (Calcic / Hypercalcic Red Dermosol)
Loam to clay loam grading to a friable red clay with soft Class I carbonate within 50 cm, grading to alluvium within 100 cm.
D1 Loam over red clay on rock (Hypercalcic / Calcic, Red Chromosol / Sodosol)
Medium thickness hard gravelly loam over red clay, friable and finely structured, calcareous with depth, grading to weathering basement rock within 100 cm.
D2 Hard loam over red clay (Calcic / Hypercalcic, Red Chromosol)
Hard setting sandy loam to clay loam (with variable quartzite stones) abruptly overlying a well structured red clay with soft Class I carbonate at depth.
D4 Loam over red friable clay (Calcic, Pedaric, Red Sodosol)
Thin to medium thickness fine sandy loam to loam over a finely structured friable red clay, calcareous from about 50 cm, grading to fine or medium grained alluvium.
E2 Red cracking clay (Epicalcareous, Epipedal, Red Vertosol)
Dark strongly structured clay grading to a well structured red calcareous medium to heavy clay continuing below 100 cm. Often containing gypsum segregations in subsoil.
J1 Ironstone soil with calcareous lower subsoil (Ferric Calcic Brown Sodosol-Chromosol-Dermosol) Ironstone gravelly soil with a brown alkaline clayey subsoil with a calcareous layer within the profile.
Usually clay-loam topsoil with a bleached subsurface layer.
L1 Shallow stony loam (Paralithic, Leptic Tenosol)
Shallow stony loam, often calcareous throughout or with depth, overlying weathering rock shallower than 50 cm.
M1 Alluvial loam (Orthic Tenosol)
Very thick loam with variable gritty or more clayey lenses, formed over recent alluvium.
M3 Deep gravelly soil (Gravelly Kandosol-Tenosol)
Deep uniform loamy alluvial soils with at least 50% gravel in the major part of the profile.
RR Bare rock
Further information: DEWNR Soil and Land Program
